Information processing by cutaneous tactile systems may be utilized when the effectiveness of a conventional channel is limited, as in high noise environments; when existing channels are overtaxed, as in jet and space control systems; or when existing channels suffer a deficit, as in the sensory losses of deafness and blindness. Of increasing interest are the sensory characteristics associated with advancing age and those associated with pathologies that may affect neural functioning. There are still sizable gaps in our knowledge of important fundamental characteristics of the cutaneous sensory systems and that knowledge lags far behind the information that is available for the auditory and visual systems. The aim of the proposed experiments is to extend our understanding of the psychophysical characteristics of responses to vibrotactile stimulation in humans, always within the context of the possible neural/receptor mechanisms that may underlie those characteristics. The experiments fall into four general problem areas: 1) spatiotemporal aspects of vibrotactile sensation, especially those relating to the development of tactile communication devices. 2) interactions between vibrotaction and other sense modalities. 3) the effects of subject variables, such as aging and hemispheric dominance and 4) the effects of neuropathies, such as diabetes, carpal tunnel syndrome, and "white finger". The experiments are specifically targeted on exploring the functional properties of the non-Pacinian receptor systems within the context of a triplex and possibly a quadruplex model of cutaneous mechanoreception.